Combined steam and compressed-air engine.



H. G. FARR. COMBINED STEAM AND COMPRESSED AIR ENGINE. APPLICATION FILED AUG.16, 1911.

1,090,523. Patented Mar. 17, 1914.

3 SHEETS-SHEET 1.

COLUMBIA PLANOGRAPH C0. WASHINGTON. D c.

H. G. FARR.

COMBINED STEAM AND COMPRESSED AIR ENGINE.

APPLICATION FILED AUG. 16, 1911.

Patented Mar. 17, 1914.

3 SHEETS-SHEET 2.

Wibwssas:

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G.F1rr; by 6 H. G. FARR.

COMBINED STEAM AND COMPRESSED AIR ENGINE.

APPLICATION FILED AUG. 16, 1911.

Patented Mar. 17, 1914.

3 SHEETS-SHEET 3.

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151%Farr; by 13! Wzhzesses: M46. M Q? iTNTT ED STATES COMBINED STEAM AND COMPRESSED-AIR ENGINE.

Specification of Letters Patent.

Application filed August 16, 1911.

Patented Mar. 17,1914.

Serial No. 644,449.

To all whom it may concern Be it known that I, HIRAM G. FARR, a citizen of the United States of America, and a resident of Melrose, in the county of MiddleseX and State of Massachusetts, have invented certain new and useful Improvements in Combined Steam and Compressed- Air Engines, of which the following is a specification.

This invention relates toengines, and has for its object the provision of a supple mental source of power which may be utilized either in conjunction with the primary source of power or independently thereof, as maybe desired.

It consists in the provision of a storage tank in which air is adapted to be forced under pressure by the driving mechanism when the latter is being actuated by the primary power and from which compressed air may be admitted to the steam chest at will, either to serve as an independent source of power to drive the piston or to commingle with the steam and increase the pressure obtained therefrom.

The invention further consists in providing a means for heating said compressed air prior to its admission to said steam chest to substantially the same temperature of the steam therein.

The invention further consists in certain novel features of construction and arrangement of parts which willbe readily understood by reference to the description of the drawings and to the claims hereinafter given.

Of the drawings: Figure 1 represents in diagram a locomotive engine, partially broken in section, and showing the features of the present invention applied thereto. Fig. 2 represents an enlarged sectional detail of the steam and air inlets to the steam chest. Fig. 3 represents a vertical section of an air pump for forcing air under pressure into the storage reservoir.

Similar characters designate like parts throughout the several figures of the drawm s.

Tn the drawings, 10 represents a locomotive of any well-known construction provided with driving wheels 11 connected by means of the connecting rod 12 to a piston rod 13 having secured thereon a piston 14 adapted to reciprocate in the cylinder 15. Above the cylinder 15 is a steam chest 16 in which is mounted a valve 17, which may be of any well-known construction, and is reciprocated by means of the valve rod 18 to admit steam or other fluid pressure alternately into opposite ends of the cylinder 15. This valve rod 18 is operable by the reciprocation of the pis ton rod 13 in any well-known manner, the details of construction of said valve operating mechanism being omitted as they form no part ofthe present invention. Secured to the valve chest cover 19 is a tubular member 20, with the interior of which the pipe 21 communicates, this pipe 21 leading from the steam dome 22 above the usual boiler 23. The pipe 21 has a valve 24 which is adapted to control the steam passing from the pipe 21 into the tubular member 20. Partially surrounding the boiler 23 is a storage tank or reservoir 25 adapted to receive air under pressure, said air being forced into said tank or reservoir 25 through the pipe 26 leading from an air pump 27, operable by means of an eccentric 28 secured to and revolving with the axle 29 of one pair of driving wheels 11. While for convenience this eccentric 28 is shown mounted upon the axle 29 of the driving Wheels, it is obvious that it may be mounted upon any other revoluble member actuated by the reciprocatory movement of the piston 14, without altering the principles of the present invention. The pump 27 is of any wellknown construction, the body portion being cylindrical and having mounted therein a piston 30, pivotally connected to the upper end of the eccentric rod 31 in such a manner that each cycle of the eccentric 28 causes a complete reciprocation of the piston 30. The pump is provided with the usual air inlet valve 32 and outlet valve 33. During the downward movement of the piston 30 the suction will cause the valve 33 to close and the valve 32 to open to permit air to be admitted to the interior chamber of the pump, and on its return movement the valve 32 will be immediately closed and the air in the pump chamber will be forced through the pipe 26 into the tank 25. This tank is provided with a suitable relief valve 34 to permit the escape of any excessive amount of air when a certain degree of compression has been reached. The compressed air in the tank 25 is permitted to pass therefrom through a coil of pipe 35 extending through the boiler 23 and terminating in the nozzle 36within the tubular member 20. This pipe 23 is provided with a valve 37 by which the passage of the air through said pipe may be controlled at will. The end of the tubular member is provided with suitable stufling box 38 surrounding said pipe 35 at its point of admission into said tubular member, thereby preventing any leakage of steam therefrom. The storage tank 27 is superimposed upon and partially surrounds the boiler 23 so that a certain degree of heat is maintained therein at all times, and all compressed air passing therefrom through the pipe 35 comes in contact with the heated gases of the boiler 23 and causes the air to be heated to substantially the same temperature as the steam passing from the steam dome 22 into the steam chest 16 through the pipe 21 and tubular member 20. This heating of the air to a high degree of temperature before it is admitted to the steam chest prevents cool air, upon admission thereto, from condensing the steam being admitted through the tubular member 20. The mouth of the tubular member 30 is contracted as indicated at 39, thereby producing, in conjunction with the nozzle end 36 of the pipe 35, a blower effect which causes the air and steam to commingle as they enter the steam chest, When the valves 24 and 37 are both open.

It is obvious that when the engine is in operation the reciprocation of the piston 14 will cause a rotation of the axle 29, thereby operating the pump 27 through the eccentric 28, and a continuous supply of air under pressure will be forced into the storage tank or reservoir 25, the amount of compression of said air being limited by the setting of the relief valve 34, which may be of any well-known construction. As the pipe 35 is in constant communication with the storage tank 25, the compressed air contained in the tank and the pipe 35 is subjected to the heat of the boiler 23 at all times, and is always in condition for use, Should the steam pressure being admitted through the tubular member 20 to the steam chest 16 be reduced at any time, and it be desired to maintain a usual pressure the valve 37 may be opened a greater or less degree, the compressed air admitted to the steam chest thus acting in conjunction with the steam pressure therein, thereby increasing its actuating power. It is obvious, also, that even when the steam pressure is shut off for any cause by closing the valve 24, the compressed air from the tank 25 may be admitted to the steam chest and the piston lL operated thereby. It is self-evident, therefore, that in the construction of engine shown and described herein, provision is made whereby the driving mechanism may be actuated either by steam pressure alone, compressed air alone, or the two'pressures may be combined to obtain a more effective result. This is of great advantage, and it is obvious that a construction as is herein shown may be utilized in many ways too numerous to mention.

It is preferable that the tank 25 should be supplied with compressed air from the pump 27 only when there is no load on the engine, as for instance, when it is on a down grade. For this reason a stop valve 40 is provided in the pipe 26 which is adapted to shut off the supply of air to said tank, the pump being provided with an outlet valve 41 which is adapted to be closed when the valve 40 is open and vice versa. To the valve plugs of these valves 4c0-fl:l are secured arms 42, pivotally connected to a reciprocating rod 43 provided at one end with a handle M which may be operated by the engine driver to move both valves in unison when desired. This means of placing the pump out of commission when desired and immediately placing it in operation again to give an additional supply of compressed air to the tank 25 when needed forms an important feature of. the present.

invention.

It is evident that while one embodiment of mechanism is shown in the drawings and described herein for securing the result desired, any other form of mechanism capable of performing the same function may be used without altering the principles of this invention.

It is believed that the operation and many advantages of the invention will be fully understood from the foregoing.

Having thus described my invention, I claim:

1. The combination with a steam-driven locomotive having a steam chest and a cylinder supplied thereby, of means mounted on and actuated by movements of the locomotive for storing air under compression, and connection between the stored air and the steam chest for admitting air to the chest at will independently of the steam supply, whereby the cylinder supply may becomposed of either steam or air or a combination of both, said connections extending into the steam space of the locomotive whereby the air supplied to the chest will be heated.

2. The combination with a steam-driven locomotive having a steam chest and a cylinder supplied thereby, of means mounted on and actuated by movements of the locomotive for storing air under compression, and connections between the stored air and the steam chest for admitting air to the chest at will independently of the steam supply, whereby the cylinder supply may be composed of either steam or air or a combination of both, said connections extending Signed by me at 4 P. 0. Sq., Boston, into the steam space of the locomotive Mass, this 8rd day of August, 1911. whereby the air supplied to the chest Will be heated, the connections outlet being at the HIRAM FARR steam entrance to the steam chest to provide Witnesses:

a mixture Where air and steam are used in WALTER E. LOMBARD, combination. NATHAN O. LOMBARD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner 0! Petente, Washington, D. G. 

